I'm looking for (1) matching mortise lock set and (1) matching/comparable jamb latch.

Hi there!

Thank you for reaching out to us. Take a look at the 82-218 mortise lock, which resembles what you show here. We don't sell your exact keeper, but the 89-020, 89-021, and 89-021D are compatible with our lock. Review the specifications for these parts and see how they compare with your old hardware. 

Opposite side view 82-218

Profile view of 82-218

Alternate image for 89-020

Alternate image for 89-021

Alternate image for 89-021D